Description🧾

A plugin which adds an AOS (Area of Sight) node for 2D. Often used of showing a danger area in stealth games.

Exapmle

Contents📰

This plugin adds two nodes:

• AreaOfSight2D (extends Node2D)
• AreaOfSightAgent2D (extends Area2D)

AreaOfSight2D

This node is an AOS itself. You can see all the properties below:

All this parameters are desribed in the docs and in the comments in the code.
The procedurally generetion is made with spreading rays in different directions. I didn't use Ray2D, it would be too slow. Instead I used PhysicsDirectSpaceState2D.intersect_ray.

AreaOfSightAgent2D

This is an interesting one. AreaOfSight2D doesn't work with any CollisionObject2D (like Area2D, CharacterBody2D ect). Instead you have to use AreaOfSight2D. The node itself is just an Area2D but with some additional parameters.

Agents has a member target_points, which is a PackedVector2Array. This array contains points which the AreaOfSight2D will use to consider if the agent is seen or not.

The red points are contained in target_points. As you can see, they are located in a cirlce (the center of this circle is also in target_points). The target_points_amount will change the size of target_points. The larger the value, the more accurate the calculations will be. But don't increase the target_points_amount, it can result in lags. In my opinion, the value of 8 is perfect for small objects. It's better to set the values that are a power of 2 (4, 8, 16, 32...). To decide if the agent is in the area of sight I iterated over target_points and applied Geometry2D.is_point_in_polygon to each target point.

Why agents?🤔

At first a planned to make an AreaOfSight extend Area2D and change its CollisionPolygon2D shape in the process. Although this method is obvious, it had a huge problem: when the area shape is redrawn, the collisions of Area2D are recalculated. This contributed to some problems with tracking other areas and bodies while changing area's shape. That's why I decided to create an agent node.

Getting started✅

• Install the plugin;
• Enable the plugin in project setiings;
• Find AreaOfSigth2D in list of classes;
• Create a simple enemy scene:
  
• Add some walls (using Tilemap or CollisionObject2D) and player scene;
• Add AreaOfSightAgent2D to player's scene;
• Configure collision layers and masks;
• Connect node_entered_area and node_exited_area signals to some action (like changing color of the AOS or printing something in the console)
• Have fun with AreaOfSight2D and AreaOfSightAgent2D parameters!

It's also highly recommended to check the example scene. You can struggle with agents or collision layers, so check how I did it.

When to use?🧐

You can use my AOS node for these scenarios:

1. You need to visualize the AOS. Usually needed in stealth games;
2. You need make you enemies (or other objects) track not only a player (in this case just use the Ray2D) but all the nodes like items, other enemies ect;
3. You want to make something like lighting without shaders.

Compatibility🎯

• Godot version 4.0+;
• Tested on Godot 4.2.1;
• Tested with Compatibility renderer. Should work on Mobile and Forward+ as well;
• Only for 2D projects;
• The lower amount of rays the AOS uses and the smaller target_points_amount is, the faster your game will work!

License🪪

The librarry asset uses LGPL 3.0.